A Guild Navigator was a senior rank of artificially super-evolved humans within the Spacing Guild and for many Guildsmen the pinnacle of their ambitions. Mutated through the consumption of and exposure to massive amounts of the spice Melange, Navigators are able to use a mentally conditioned and trained form of prescience to safely navigate interstellar and galactic space in long-range starships called Heighliners.
To enable their prescience, Guild Navigators not only consume large quantities of the spice, but are also continuously immersed in highly-concentrated amounts of orange spice gas housed in large tanks. Also, they were notorious for participating in massive spice orgies. This level of extreme and extended exposure causes their bodies to atrophy and mutate over time, their heads and extremities elongating. The first external sign of melange-induced metabolic change is visible in the eyes, as the drug tints the sclera and iris to a dark shade of blue. The shade of blue is known to be called "blue-in-blue" or "the Eyes of Ibad," "a total blue so dark as to be almost black." This is a common side effect in all spice addicts.
In the original 1965 novel Dune, Duke Leto Atreides notes that the Guild is "as jealous of its privacy as it is of its monopoly," and that not even their own agents ever see Navigators. Leto's son Paul wonders if they are mutated to the point of no longer appearing human. A Navigator is fully revealed in the first chapter of Dune Messiah (1969). Here, the Guild Navigator Edric is called a "humanoid fish," and described in his tank of spice gas as "an elongated figure, vaguely humanoid with finned feet and hugely fanned membranous hands — a fish in a strange sea." The Navigators' "elongated and repositioned limbs and organs" are noted in Heretics of Dune.
In 1985's Chapterhouse: Dune, Lucilla notes that "Navigators were forever bathed in the orange gas of melange; their features often fogged by the vapors," that they possess a "tiny v of a mouth" and "ugly flap of nose" and that "Mouth and nose appeared small on a Navigator's gigantic face with its pulsing temples." She also notes that their mutated voices require translation devices, describing "the singsong ululations of the Navigator's voice with its simultaneous mechtranslation into impersonal Galach."
In an unused passage from Dune Messiah published in The Road to Dune (2005), Edric is described as surviving without spice gas once a hole is opened in his tank, though his prescient abilities are practically useless in this state.
In David Lynch's 1984 film Dune, the Navigator's mutation affects his entire body, with 3rd stage navigators resembling either a giant whale or slug with a heavily deformed head. He also has a V-shaped mouth and vestigial limbs suspended in huge tanks of orange spice-gas. He is not shown to have the blue-in-blue eyes of a spice addict, however. The movie also states that it is the Navigator itself that folds space, and not the Heighliner's engines. Frank Herbert reportedly liked the idea of different stages of navigators as mentioned in the 1984 film and incorporated it into his later books.
In the 2000 miniseries adaptation and the subsequent Children of Dune miniseries, the appearance of the Navigators mostly adheres to the description in Dune Messiah, resembling a semi-humanoid manta ray. Additionally, the guild agents are portrayed as bald men in flowing robes with peaked caps. They're often seen with their arms crossed or with their hands pressed together, strongly implying that they are in the process of becoming Navigators themselves.
In the 2021 film, Guild representatives appear humanoid, but their physical features are obscured by ornate white robes and an opaque spherical helmet. These, however, are unlikely to be Navigators, as Thufir Hawat includes three Navigators in his calculations of cost of the trip, while there are more than three of these representatives present.
Role in the Spacing Guild
Guild Navigators were responsible for guiding space-faring ships (spacefolders) through the mine-field of gravitational obstacles that lay between a source and a planetary or spatial target. They accomplished this feat by using prescient abilities brought on by excessive exposure to the Spice Melange. The navigators would either inhale massive amounts of orange spice gas or swallow spice pills, which would afford them the ability to see across vast distances of space, and importantly, into the near future, though spacefolding travel allowed through the application of the Holtzman Effect resulted in the loss of a ship roughly one in every ten journeys. A Navigator's keen senses would be able to plot safe courses for ships across vast distances of space by presciently determining unsafe routes, before a fold actually takes place, via prescience.
Guild Navigators effectively replace Navigational computers used in the days of old. During The Butlerian Jihad, all "thinking machines" were gathered and destroyed, with a commandment against their usage, "Thou shalt not make a machine in the likeness of a human mind". Instead humanity now relies on Navigators and their prescient abilities to determine safe routes throughout the cosmos.
Because of their limited prescient abilities, Guild navigators were capable of seeing minor aspects of Paul Atreides' grand designs. Guild Navigators perceived Paul as a threat to their power and indeed the stability of the universe as a whole.
This led to the Guild being complicit in the attack against House Atreides by House Harkonnen shortly after the former took control of Arrakis. A Guild Navigator participated in a conspiracy, as well, to assassinate Paul some twelve years after he became Emperor. The Navigator was primarily used to shield the conspiracy from Paul and those others who had prescient abilities.
A prominent character In 1969's Dune Messiah; Edric takes part in a plot against the emperor, Paul Atreides, the other conspirators being the Bene Gesserit Reverend Mother Gaius Helen Mohiam, the Tleilaxu Face Dancer Scytale, and Paul's embittered wife, Princess Irulan of House Corrino. Edric's involvement is solely to protect the conspirators from discovery by Paul's prescient sight, as the presence of a prescient such as Edric hides the activities of that person and those around him from other prescients. After the plot fails, Edric and Mohiam are executed in 10,207 A.G. by Fremen Naib Stilgar on orders from Paul's sister Alia Atreides.
In Chapterhouse Dune (1985), a "very powerful" Navigator is described as "one of the Edrics," suggesting a possible breeding plan or use of a series of ghola based Edric clones.
In Lynch's 1984 movie, Edric (who is a 3rd stage Navigator) visits Emperor Shaddam IV at the beginning of the movie and asks for information about the plot against House Atreides which Shaddam reveals. After hearing the plot, Edric adds a detail: Paul Atreides must be killed at all costs. Edric leaves, leaving Shaddam IV wondering why the Guild Navigator wants the Duke's son killed. This is overheard by Reverend Mother Mohiam who subsequently goes to Caladan.
- The Guild Navigators have found themselves to be the inspiration for several creatures and characters in science fiction. Examples include the Navigators from Warhammer 40,000, the Advisors from Half-Life 2, the Aurora Unit from Metroid Prime 3: Corruption, and quite possibly Melfina from Outlaw Star. Further examples might also include the Cylon hybrids who serve as navigators and central computers in the Re-imagined Battlestar Galactica series and the Tardigrade in Star Trek: Discovery .